三种荒漠植物种子萌发的水热响应  

Germination responses of three desert plants to temperature and water potential

作　　者：黄文达[1] 王彦荣[1] 胡小文[1] 

机构地区：[1]兰州大学草地农业科技学院,甘肃兰州730020

出　　处：《草业学报》2009年第3期171-177,共7页Acta Prataculturae Sinica

基　　金：国家基础研究发展计划(973项目)(2007CB108904)资助

摘　　要：种子萌发水热模型量化了温度和水分对种子萌发的作用,是开展种子生理生态研究的重要方法之一。本研究测定了采自内蒙古阿拉善干旱荒漠区的无芒隐子草、多裂骆驼蓬和雾滨藜3种荒漠植物种子在15,20,25,30℃恒温-、2.1~0 MPa水势条件下种子的累计萌发率和萌发速率(1/t50),利用水热模型对萌发的水分时间累计值(θH)和温度时间累计值(θT)进行了估测。结果表明,3种供试植物种子的累计萌发率与水分呈极显著正相关(r2=0.54~0.93,P<0.01);除多裂骆驼蓬(发芽率未达到50%)外,其他2种植物种子的萌发速率也与水分呈极显著正相关(r2=0.66~0.95,P<0.01)。3种种子萌发的水分时间累计值的变化因温度而异,在15~25℃内都表现为多裂骆驼蓬<雾滨藜<无芒隐子草;萌发的温度时间累计值(θT)亦因渗透势的变化而变化,在0^-1.5 MPa水势间都表现为多裂骆驼蓬<雾滨藜<无芒隐子草。The hydrothermal model that quantifies seed germination progress affected by temperature and water potential, is one of the important methods in the physiological and ecological researches of seed. Seed germination percentage and germination rates （1/t50） of three desert plants Cleistogenes songorica, Peganum multisecturn and Bassia dasyphylla collected from Alashan desert grassland, Inner Mongolia were estimated under the water potential ranging from -2. 1 to 0 MPa at 15, 20, 25, and 30℃. The hydrotime （θH） and thermaltime （θr） were estimated by using the hydrothermal model. Significant positive correlations were observed between the germination percentages of three desert plants and the osmotic potentials （r^2 =0.54-0.96, P（0. 01）, and between the germination rates （1/t50） and the osmotic potentials （r^2 =0.66-0.95, P〈0. 01） except P. multisectum （ of which the germination percentage was less than 50% from -2.1 to 0 MPa at 15, 20, and 25℃）. θn varied with temperature change （P〈0. 05） from 15 to 25℃ appearing P. multisectum〈B, dasyphylla〈C.songorica. And Or varied with osmotic potential change from -1.5 to 0 MPa, showing similar order.

关 键 词：水热模型 水分胁迫 温度 种子萌发 无芒隐子草 雾滨藜 多裂骆驼蓬 

分 类 号：S311[农业科学—作物栽培与耕作技术]